In the eighteenth century, the kilns at Jingdezhen began to make porcelains of a different material. Known as huashi, or "slippery stone," this expensive material, often called soft paste, was used to make thin vessels that frequently were decorated with incised or raised designs under glaze. While the reasons for its introduction remain unclear, soft paste is easily carvable, and its use would have thus been akin to contemporaneous interests in the manipulation of other materials such as ivory and bamboo.